1. Field of the Invention
This invention relates to communication systems, and more particularly, usage-based billing for voice communications transmitted over a packet system.
2. Description of the Prior Art
Conventional long-distance telephone calls are billed based upon the time that a circuit connects the calling party to the called party. A long distance switch, that connects a telephone of the calling party to a Public Switched Telephone Network (PSTN)-based system, collects billing information for the call. The long distance switch generates call detail records based on the billing information. The call detail record includes the calling party, the called party, the time of day the call was made, and the length of time of the call. The length of time of the call is the amount of time that a circuit connects the two parties. Because the length of time and time of day of a call are easy to determine, such information has typically been used to bill for telephone calls. The long distance switch transfers the call detail records to a PSTN billing system. The PSTN billing system processes the call detail records to generate bills for the calls placed over the PSTN-based system.
Unfortunately, it is difficult for a long distance switch to determine the length of time of a voice communication transmitted over packet network. In a packet network, a user speaks into a telephone that is connected to a switch. For purposes of this discussion, a switch may be a traditional switch, a router, or any other gateway. The switch converts the analog voice signals into digital voice signals. The switch encodes the digital voice signals into packets. The switch then transmits the packets over the packet network to another switch that is connected to the called party.
In a typical voice over packet network, a signaling processor enables communication between parties by determining an address, such as an Internet Protocol (IP) address, for both the called party and calling party. The signal processor then uses messages to inform both the calling party switch and the called party switch of the addresses determined for the communication. The switches then route the packets carrying the voice data back and forth between the parties to provide the voice communication.
Unfortunately, it is not currently practical to bill voice communications over a packet network in the same manner, and using the same billing system, as traditional circuit voice telephone calls. Thus, most providers charge a flat rate for communications because there is no convenient way to quantify use of the network. For instance, it is difficult to count the number packets sent between parties to bill on a per-packet basis. Also, no connection is maintained between the switches in a packet network, which makes determining the length of time of a call difficult. Being unable to utilize the existing billing systems is a particular problem as more voice communications are moved to packet networks to take advantage of increased bandwidth and redundancy that packet networks provide.